Apocrine Breast Cancer
Apocrine carcinoma of the breast is a rare cancer which originates in ducts. It’s name comes from its cells that resemble sweat glands, but it’s just a resemblance. It did not actually develop from sweat glands.
You can’t predict the diagnosis of apocrine carcinoma, because on a mammogram or ultrasound, it looks like just about every other kind of breast cancer.
A confirmed diagnosis requires a biopsy which shows a malignant tumor with predominantly apocrine characteristics.
Some pathologists argue that it should be considered a ‘sub-type’ of breast carcinoma because of its unique microscopic appearance, although there are no clinically significant differences from other ductal carcinomas.
‘Apocrine’, generally speaking, refers to cells that do ‘secretion’. For example, in a true sweat gland, the cells are grouped together for the purpose of secreting ‘sweat’ to the skin. A small number of cells resembling true apocrine cells are found in the breast, and they may develop carcinoma. Apocrine literally means ‘apex’, and apocrine cells secrete fluids by ‘budding-off’ the top of the cell, causing membrane-bound vesicles (bubbles of fluid) to accumulate in the lumen above the ‘free-end’ of cells. ( Normally, this fluid is released externally to the skin, as sweat.)
Statistical Prevalence of Apocrine Breast Carcinoma
Apocrine carcinoma is rare, and mostly effects women in theirs 60’s and 70’s, with an average age of 65. Statistically apocrine carcinoma accounts for around 4% of all breast cancers.
Histological Characteristics of Apocrine breast cancer cells
By gross appearance apocrine breast tumors are generally indistinguishable from other invasive breast carcinomas. When examined by a microscope apocrine breast tumors usually appear as sheets, cords, and sometimes tubules of neoplastic cells. The most obvious cytological features of apocrine carcinoma are large amounts of eosinophilic, granular cytoplasm ( containing particles or grains, which stain more easily), tumor cells with well-defined margins, and large vesicular nuclei which are often round or oval. The nucleus to cytoplasm ratio is about 1:2. Apocrine carcinoma cells frequently reveal ‘apocrine snouts’. These ‘snouts’ are actually accumulations of secreted granules in the apical cytoplasm ( the cytoplasm around the top or free-end of the cell, spilling into the lumen of the breast ducts), that is clearly revealed by staining dyes.
Hormonal features of apocrine breast cancer
Apocrine carcinomas tend to test negative for estrogen and progesterone receptors, but there is quite a wide variability for both hormones. Apocrine tumors have been shown to be HER-2 positive about 50% of the time, and breast cancers quite commonly test positive for androgen receptors, between 55 and 100% of the time.
This page has old information. The ER PR HER2 status, and the treatment implications of that, probably has some new information that I don’t know about, because I’m a radiologist, not an oncologist.
Apocrine Carcinoma often mistaken for more benign conditions
A diagnosis of apocrine breast carcinoma is made only after careful differentiation for other common, benign breast diseases with apocrine cell involvement. A suspected apocrine carcinoma is commonly revealed to be Apocrine Metaplasia (ACMA), a condition which quite common in younger, premenopausal women. It is a bit of a controversial issue, but there is no proven relationship between apocrine metaplasia and subsequent development of apocrine carcinoma.
Another common, benign breast disease mistaken as apocrine carcinoma is gross cystic disease of the breast, often called GCDFP-15 for the ‘fluid protein 15’ found in the discharges. That condition is the result of a kind of ‘over-production’ of apocrine secretions and is also common in premenopausal women. But, the GCDFP-15 protein also tests strongly positive with most apocrine carcinomas, so a pathologist has to be very thorough to make sure there is no mistake.
Prognosis for Apocrine breast cancer
The prognosis for apocrine breast cancer is not particularly good, and is basically the same as for invasive ductal carcinomas generally. While some studies show a slightly better prognosis for apocrine carcinoma, overall there is no statistical advantage when matched by stage and grade. The six year survival rate for moderate to high grade apocrine breast cancer is thought to be between 70% and 80%. There is some evidence to suggest that lymphatic invasion and lymph node metastasis is less likely for apocrine carcinoma than for non-specific invasive ductal carcinoma, but this is a relatively new finding which has not been broadly confirmed.
Being that this page is old, and knowing that cancer survival rates have significantly improved since I wrote it, just assume that paragraph giving survival rates, is underestimating. Oncologists can tell you the latest knowledge.
- Japaze H, Emina J, Diaz C, Schwam RJ, Gercovich N, Demonty G, Morgenfeld E, Rivarola E, Gil Deza E, Gercovich FG. ‘Pure’ invasive apocrine carcinoma of the breast: a new clinicopathological entity? Breast. 2005 Feb;14(1):3-10.
- Tanaka K, Imoto S, Wada N, Sakemura N, Hasebe K. Invasive apocrine carcinoma of the breast: clinicopathologic features of 57 patients. Breast J. 2008 Mar-Apr;14(2):164-8.
- Eom, Min-Seob., Park,Jin-Kyu., Jung, Soon-Hee.,Lee, Wang-Gil.,The Fine Needle Aspiration Cytologic Features of Apocrine Carcinoma of the Breast – A Case Report -. Korean Journal of Cytopathology. Vol.14, No.2:76-81, September 2003
- Jayaram, Gita., Har Yip, Cheng., Binti Yaccob, Roshidah., Apocrine carcinoma of the breast diagnosed on fine needle aspiration cytology Acta Cytologica v. 51, n. 4 2007-07-08,p. 664-666
- Eusebi V, Millis RR, Cattani MG, Bussolati G, Azzopardi JG. Apocrine carcinoma of the breast. A morphologic and immunocytochemical study. Am J Pathol 1986;123:532-541.
- Tavassoli FA, Norris HJ. Intraductal apocrine carcinoma: a clinicopathologic study of 37 cases. Mod Pathol 1994;7:813-818.
- Yerushalmi, R., Hayes, M.M., Gelmon, K.A., Breast carcinoma—rare types: review of the literature.Annals of Oncology 2009 20(11):1763-1770
- O’Malley FP, Bane A. An update on apocrine lesions of the breast. Histopathology (2008) 52(1):3–10
- Miller WR, Shivas AA, Franchimont P, et al. Breast gross cystic disease protein 15 in human breast cancer in culture. Eur J Cancer Clin Oncol (1988) 24(2):223–228
- Washington, C. Dalbegue, F. Abreao, F., Taubenberter, JK, and Lichy, JH. Loss of heterozygosity in fibrocystic change of the breast: genetic relationship between benign proliferative lesions and associated carcinomas. American Journal of Pathology 2000, 157: 323-329
Back to Types of Lesions list.